From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 5F1948D0039 for ; Mon, 21 Mar 2011 11:23:47 -0400 (EDT) Message-ID: <4D876D43.3020409@fiec.espol.edu.ec> Date: Mon, 21 Mar 2011 10:22:43 -0500 From: =?ISO-8859-1?Q?Alex_Villac=ED=ADs_Lasso?= MIME-Version: 1.0 Subject: Re: [Bugme-new] [Bug 31142] New: Large write to USB stick freezes unrelated tasks for a long time References: <4D80D65C.5040504@fiec.espol.edu.ec> <20110316150208.7407c375.akpm@linux-foundation.org> <4D827CC1.4090807@fiec.espol.edu.ec> <20110317144727.87a461f9.akpm@linux-foundation.org> <20110318111300.GF707@csn.ul.ie> <4D839EDB.9080703@fiec.espol.edu.ec> <20110319134628.GG707@csn.ul.ie> <4D84D3F2.4010200@fiec.espol.edu.ec> <20110319235144.GG10696@random.random> <20110321094149.GH707@csn.ul.ie> <20110321134832.GC5719@random.random> In-Reply-To: <20110321134832.GC5719@random.random> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Mel Gorman , Andrew Morton , avillaci@ceibo.fiec.espol.edu.ec, bugzilla-daemon@bugzilla.kernel.org, bugme-daemon@bugzilla.kernel.org, linux-mm@kvack.org El 21/03/11 08:48, Andrea Arcangeli escribio: > > === > Subject: mm: compaction: Use async migration for __GFP_NO_KSWAPD and enforce no writeback > > From: Andrea Arcangeli > > __GFP_NO_KSWAPD allocations are usually very expensive and not mandatory > to succeed as they have graceful fallback. Waiting for I/O in those, tends > to be overkill in terms of latencies, so we can reduce their latency by > disabling sync migrate. > > Unfortunately, even with async migration it's still possible for the > process to be blocked waiting for a request slot (e.g. get_request_wait > in the block layer) when ->writepage is called. To prevent __GFP_NO_KSWAPD > blocking, this patch prevents ->writepage being called on dirty page cache > for asynchronous migration. > > [mel@csn.ul.ie: Avoid writebacks for NFS, retry locked pages, use bool] > Signed-off-by: Andrea Arcangeli > Signed-off-by: Mel Gorman > --- > mm/migrate.c | 48 +++++++++++++++++++++++++++++++++--------------- > mm/page_alloc.c | 2 +- > 2 files changed, 34 insertions(+), 16 deletions(-) The latest patch fails to apply in vanilla 2.6.38: [alex@srv64 linux-2.6.38]$ patch -p1 --dry-run < ../\[Bug\ 31142\]\ Large\ write\ to\ USB\ stick\ freezes\ unrelated\ tasks\ for\ a\ long\ time.eml (Stripping trailing CRs from patch.) patching file mm/migrate.c Hunk #1 FAILED at 564. Hunk #2 FAILED at 586. Hunk #3 FAILED at 641. Hunk #4 FAILED at 686. Hunk #5 FAILED at 757. Hunk #6 FAILED at 850. 6 out of 6 hunks FAILED -- saving rejects to file mm/migrate.c.rej (Stripping trailing CRs from patch.) patching file mm/page_alloc.c Hunk #1 FAILED at 2085. 1 out of 1 hunk FAILED -- saving rejects to file mm/page_alloc.c.rej I will try to apply the patch manually. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org